Financial Times: recruitment freeze and restrictions on travel until Christmas. Photograph: Frank Baron for the Guardian

The Financial Times has imposed a recruitment freeze and a ban on all but the most essential travel, to control costs in a tough advertising market.

John Ridding, the Financial Times chief executive, outlined the measures in an internal email on Tuesday to the newspaper's senior management group titled "Cost control/profit protection", seen by MediaGuardian.

The measures, which apply to all staff, include a freeze on recruitment and stricter rules on travel expenses.

"Unless there is a clear commercial opportunity that will deliver this year, or an essential editorial trip, we should let our global network do the work (that is what it is there for)," said Ridding. "Only the most vital of journeys will be approved."

He said that board members will also be focused on finding revenues and saving costs so staff should not take up their time with non-essential and non-urgent requests.

The measures will run until Christmas and have been implemented following a marked downturn in the advertising climate, including weak third-quarter performances by Sir Martin Sorrell's WPP and Maurice Lévy's Publicis Groupe.

"As you'll probably have noticed from recent results publications and statements from advertising agencies and news media groups, the advertising market has taken another turn for the worse," Ridding said. "And while we continue to take market share, it is clear that conditions have become tougher and that the overall advertising 'pie' is under pressure. Visibility, too, is very poor."

He said that the run-in to the end of the year is a "crucial time" with some "important [advertising] booking weeks" ahead.

"Given the need to ensure we meet our targets and protect profits, and given the lack of visibility, we need to be extremely tight and rigorous on costs," he added.

Overall Pearson reported flat underlying revenues in the first nine months and a 5% fall in operating profit.

FT Group, which includes the Financial Times and Pearson's 50% stake in the Economist, performed well with underlying revenues up 7% for the period.

However, Pearson noted that the advertising market "remains weak and short term".

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